Touchscreen Electrode Arrangement

ABSTRACT

A touchscreen includes an array of first electrode pairs and an array of second electrode pairs distributed across an active area of the touchscreen. The first and second electrode pairs may be configured in various snaking patterns to vary the proportion of first and second electrode pair density in a first direction across the touchscreen. The position of a touch can be determined by the proportion of densities of elements in the area of the touch, such as by measuring capacitive coupling of the drive elements.

BACKGROUND

Touchscreen displays are able to detect a person's touch within theactive or display area, such as detecting whether a finger is pressing afixed-image touchscreen button or detecting the presence and position ofa finger on a larger touchscreen display. Some touchscreens can alsodetect the presence of elements other than a finger, such as a stylusused to generate a digital signature, select objects, or perform otherfunctions on a touchscreen display.

Use of a touchscreen as part of a display also allows an electronicdevice to change the display image, presenting different buttons,images, or other regions that can be selected, manipulated, or actuatedby touch. Touchscreens can therefore provide an effective user interfacefor cell phones, GPS devices, personal digital assistants (PDAs),computers, ATM machines, appliances, and other such devices.

Touchscreens use various technologies to sense touch from a finger orstylus, such as resistive, capacitive, infrared, and acoustic sensors.Resistive sensors rely on touch to cause two resistive elementsoverlaying the display to contact one another completing a resistivecircuit, while capacitive sensors rely on the capacitance of a fingerchanging the capacitance detected by an array of elements overlaying thedisplay device. Infrared and acoustic touchscreens similarly rely on afinger or stylus to interrupt infrared or acoustic waves across thescreen, indicating the presence and position of a touch.

Capacitive and resistive touchscreens often use transparent conductorssuch as indium tin oxide (ITO) or transparent conductive polymers toform an array over the display image, so that the display image can beseen through the conductive elements used to sense touch. The size,shape, and pattern of circuitry have an effect on the accuracy of thetouchscreen, as well as on the visibility of the circuitry overlayingthe display. Although a single layer of most suitable conductiveelements is difficult to see when overlaying a display, multiple layerscan be easier to see.

Further, more complex patterns of touchscreen elements can require morecomplex routing of lines connecting the elements to external circuitryused to sense touch, such as external circuitry that drives varioustouchscreen elements and that detects capacitance between multipletouchscreen elements.

For these and other reasons, efficient and effective design oftouchscreen display elements is desired.

SUMMARY

A touchscreen display assembly includes an array of capacitively coupledelectrode pairs distributed across an active area of the touchscreen.Electrode pairs may be configured in various snake patterns to vary therelative density between electrode pairs across the touchscreen. In someembodiments, pairs of closely spaced drive and receive electrodes formelectrode pairs have varying snaking paths to vary the electrode pairdensity or length across the touchscreen. The position of a touch can bedetermined by the proportion of densities of electrodes in the area ofthe touch, such as by measuring capacitive coupling of the electrodepairs.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a touchscreen assembly, consistent with the prior art.

FIG. 2 illustrates a touchscreen having electrodes that vary in degreeof snaking, consistent with an example embodiment.

FIG. 3 illustrates a touchscreen having different combinations ofelectrodes that vary in degree of snaking, consistent with an exampleembodiment.

FIG. 4 illustrates a touchscreen having electrodes that vary in degreeof snaking, along with Y receive lines that vary, consistent with anexample embodiment.

FIG. 5 illustrates a variety of electrode pair snaking patterns,consistent with an example embodiment.

FIG. 6 shows a simple mutual capacitance touch sensing system,consistent with an example embodiment.

FIG. 7 shows a touchscreen assembly overlaying a display, consistentwith an example embodiment.

FIG. 8 shows a cellular telephone having a touchscreen display,consistent with an example embodiment.

DETAILED DESCRIPTION

Touchscreens are often used as interfaces on small electronic devices,appliances, and other such electronic systems because the display behindthe touchscreen can be easily adapted to provide instruction to the userand to receive various types of input, thereby providing an intuitiveinterface that requires very little user training to use effectively.Inexpensive and efficient touchscreen technologies enable incorporationof touchscreens into inexpensive commercial devices, but thesetechnologies should also desirably be durable and have relatively highimmunity to noise, moisture or dirt, or other unintended operation toensure reliability and longevity of the touchscreen assembly.

Single layer touchscreen displays are therefore often used to controlmanufacturing costs, reduce routing complexity of multiple layers, andto ensure that the touchscreen element conductive layer is opticallytransparent when overlaying the display. Minimizing process steps toproduce the touchscreen overlay and minimizing external wiringconnections further reduce the cost of producing such a touchscreendisplay, and make interfacing the display with electronic controlcircuitry more straightforward and reliable.

FIG. 1 shows a typical example of such a single-layer mutual capacitancetouchscreen display, consistent with the prior art. Here, thecapacitance between drive electrodes (denoted with an “X”) and variousreceive or sense electrodes (designated with a “Y”) is monitored, and achange in mutual capacitance between the electrodes indicates thepresence and position of a finger. Mutual capacitance sensor circuitrymeasures the capacitance between the X electrodes and the Y electrodes,which are covered by a dielectric overlay material that provides asealed housing. When a finger is present, field coupling between the Xand Y electrodes is attenuated, as the human body conducts away aportion of the field that arcs between the X and Y electrodes, reducingthe measured capacitive coupling between the X and Y electrodes.

The X drive signals X1, X2, and X3 are here extended to varioustouchscreen drive elements using a resistor divider network chain ofresistors 101, linking the elements between the X or drive electrodesand resulting in electrical interpolation of signals from the electrodesacross the various X elements of the touchscreen. For example, the Xelement just below the X1 connection will receive a much stronger X1drive signal than an X2 drive signal, and the proportion of X1 and X2drive signal strengths that couple with the Y electrodes will indicatethe relative vertical position of a finger on the display assemblyshown. Similarly, a finger placed in the lower half of the displayassembly of FIG. 1 will impact capacitive coupling between one of the Xelectrodes having some proportion of X2 and X3 drive signals, where theproportion indicates which X element is nearest the finger.

The Y elements of FIG. 1 are similarly split into three regions and havea tapered geometry, thereby providing geometric interpolation such thata finger's presence on the far left side of the touchscreen will affectcapacitive coupling between X electrodes and a Y1 sense electrode, atouch near the center of the touchscreen will affect capacitive couplingbetween X electrodes and a Y2 sense electrode, and a touch near theright side of the touchscreen will affect capacitive coupling between Xelectrodes and a Y3 sense electrode. Touches somewhere between thecenter and sides of the touchscreen will affect capacitive coupling inproportion to the area of the tapered Y electrodes under the finger,making horizontal estimation of the finger's position determinable byevaluating the proportion of Y1, Y2, and Y3 capacitive coupling with thedrive electrodes that is disrupted due to the finger's presence.

The touchscreen of FIG. 1 relies in part in the presence of resistors101 to interpolate the X drive signals between the various X elements ofthe touchscreen, requiring not only that various conductive traces belaid down to form the touchscreen, but that the X element conductivetraces also be electrically coupled to a network of resistive materialhaving resistances that are controlled. This adds extra steps, andconsiderable cost and complexity to the production process.

One example touchscreen therefore includes capacitive touchscreenelectrodes having fine line metal element pairs in proportionallyvarying densities across the active area of a touchscreen to determineposition of a finger or other object such as a stylus. The density ofthe fine line metal electrodes vary in a more detailed example between alower density, such as a straight line, and a higher density, such as aline having a high number of zig-zags or snaking that increases theelectrode pair density or length within a given area.

FIG. 2 illustrates an example of using touchscreen line electrodesnaking to proportionally vary the density of electrode pairs in atouchscreen. Here, the density of X0 and X1 electrode pairs varies fromtop to bottom, illustrating how variation of electrode pair density inone dimension can be used to determine position of a capacitive objectnear the touchscreen.

At 201, the X0 drive electrode runs parallel and close to a Y receiveelectrode denoted Y0, and are configured as X and Y electrode pairs thatsnake across the screen such that they have a relatively long linelength and a relatively high line density in a given area. Theneighboring pair of X1 drive and Y0 receive electrodes shown at 202 arestraight, minimizing the line length across the screen as well asminimizing the line density of the X1 and Y0 line pair in a given area.

The proportional difference between the X0, Y0 and X1, Y0 electrodepairs as shown at 201 and 202 results in a different amount of linelength under a finger that covers both line pairs, resulting in agreater capacitive coupling between the finger and the denser X0, Y0line pair shown at 201 than with the straight X1, Y0 line pair shown at202. This results in a proportionally larger reduction in thecapacitance measured between X0 and Y0 than is observed between X1 andY0, indicating that the finger is touching a region having a greater X0,Y0 line pair density than X1, Y0 line pair density. This indicates thatthe finger is touching near the top of the display.

Similarly, the X0, Y0 pair of electrodes at 205 have a relatively lowline density and are straight, while the X1, Y0 pair of electrodes at206 snake such that their line density in a given area is high, suchthat a touch covering lines 205 and 206 will result in proportionallylarger reduction in the capacitance measured between X1 and Y0 than isobserved between X0 and Y0. This indicates that the finger is touching aregion having a greater X1, Y0 line pair density than X0, Y0 line pairdensity, near the bottom of the display.

The line pairs shown at 203 and 204 both have moderate line densitieswhen compared to the relatively low line density of the line pair at 202and the relatively high line density of the line pair at 201, and haveline densities that are approximately the same. Because the X0, Y0electrode pair shown at 203 is approximately a mirror of the X1, Y0electrode pair shown at 204, a finger overlaying both line pairs 203 and204 will affect the capacitive coupling of both line pairs approximatelyequally, indicating the finger is near the center of the touchscreen.

The electrode line pairs 203 and 204 are configured to have anintermediate line density such that if a finger overlaps line pairs 202and 203, near the top-middle of the touchscreen, the reduction incapacitive coupling between the X0, Y0 line pair at 203 will beproportionally larger than in the X1, Y0 line pair at 202, but not asgreat as the proportional difference in capacitance reduction observedpreviously between line pairs 201 and 202 when a finger covered thoseline pairs. The touchscreen can therefore distinguish a finger thatcovers line pairs 201 and 202 from a finger that covers line pairs 202and 203, just as it can distinguish a finger that covers line pairs 202and 203 from a finger that covers line pairs 203 and 204.

This results in five distinct vertical zones on the touchscreen exampleof FIG. 2 that can be distinguished by observing the proportion ofreduction in capacitance between X0, Y0 and X1, Y0 electrode line pairs.But, greater positional resolution can be obtained if the spacingbetween line pairs is such that a finger influences the capacitivecoupling between multiple line pairs, and the scale of the snakingfeatures of the lines is not overly large relative to the diameter of atouch.

Consider as an example a typical finger touch having a width of 5-8 mm,illustrated by the broken line region at 208 of FIG. 2. The finger touchregion overlaps only line pairs 203 and 204, and the line spacing isconfigured such that a finger touch of typical size overlaps two or moreline pairs. If the finger moves up slightly in this example, the fingerarea covers a greater portion of line pair 203 and a smaller portion ofline pair 204, sufficient to cause an increase in capacitive couplingbetween the X1, Y0 line pair at 204 and a reduction in capacitivecoupling between the X0, Y0 line pair at 203. External circuitry can usethis information to determine the position of a finger on the displaywith accuracy much greater than simply determining which of fivevertical zones is touched. A more detailed example includes fine metallines that are approximately 10 micrometers or less in width, and occupy3-7% of the total screen area, with features in approximate proportionto a finger touch region as shown in FIG. 2.

The electrode line pairs of FIG. 2 are configured so that the receiveelectrode of an electrode pair is not adjacent to the drive electrode ofa neighboring electrode pair. This largely shields the Y receive line ofeach electrode pair from capacitively coupling with the X drive line ofan adjacent electrode pair.

Some larger touchscreen embodiments will use principles similar to theelectrode line snaking interpolation methods illustrated by FIG. 2. Oneexample of a larger touchscreen is shown in FIG. 3, which illustrates atouchscreen assembly having ten X,Y electrode line pairs. Here, snakingof fine line metal touchscreen electrodes is used such thatinterpolation or proportionality between reductions in the X0, Y0 andX1, Y0 electrode pair capacitances can be used to determine the positionof a finger on the touchscreen, much as was observed in the example ofFIG. 2. The example of FIG. 2 shows use of six pairs of X drive and Yreceive lines, having line pair lengths interpolated between the X0, Y0and X1, Y0 drive signals, and the example of FIG. 3 extends this to alarger example showing eight pairs of lines interpolated between X0 andX1 drive signals, providing coverage of a somewhat larger screen area.

The example of FIG. 3 further extends its vertical coverage bytransitioning from interpolation between X0, Y0 and X1, Y0 electrodepairs, as shown at 301, to interpolation between X1, Y0 and X2, Y0electrode pairs, as shown at 302. Although the X1, Y0 electrode pairshown at 303 forming the bottom drive line pair of the touchscreenregion 301 is of similar configuration as the X0, Y0 electrode pairshown at 304, much as the X1, Y0 electrode pair 206 of FIG. 2 repeatsthe snaking configuration of the X0, Y0 electrode pair of 201, FIG. 3'sX1, Y0 electrode pair 204 also forms the top electrode pair used forinterpolation of the second zone 302.

This provides a smooth transition between touchscreen zones as a finger,stylus, or other touch moves across the electrode pair 303 between zones301 and 302. The zone 302 here simply repeats the patterns shown in zone301's electrode pairs, but interpolates between X1, Y0 and X2, Y0electrode pair rather than X0, Y0 and X1, Y0 electrode pair. Severaladditional zones can be similarly added to form even larger touchscreendisplays, scaling to whatever resolution and size is required for aparticular application.

In a further example, more zones than the number of separate X drivesignals present can be implemented, so long as each zone interpolatesbetween a different pair of X drive signals. For example, a touchscreendisplay having X0, X1, X2, and X3 drive signals may interpolate betweenX0 and X1 in a first region, X1 and X2 in a second region, X2 and X3 ina third region, X3 and X0 in a fourth region, etc. Such a scheme canenhance the resolution or size of a touchscreen that can be implementedwith a given number of drive lines, particularly when the screen isconfigured to detect single touches.

Although the examples shown illustrate a variety of ways that degree ofsnaking of X/Y touchscreen line pairs can be used to detect fingerposition in one dimension in a touchscreen display, many touchscreenembodiments will also use multiple Y receive lines in electrode pairdensities that vary in the horizontal direction to enable detection of afinger or other touch position in two dimensions.

FIG. 4 shows a more detailed example of a two-dimensional touchscreenusing line snaking, expanding the example line pairs shown at 201 and202 to use three Y receive lines Y0, Y1, and Y2. This provides touchposition determination in both the vertical and horizontal dimensions,enabling determination of finger position in two-dimensionalapplications such as smart phones, touch screen kiosks, ATM machines,and the like.

Here, the X0 line at 401 and X1 line at 402 are substantially similar inconfiguration as the corresponding X0 and X1 drive lines at 201 and 202of FIG. 2, but the Y receive line of FIG. 2 is replaced by threeseparate Y receive lines indicated Y0, Y1, and Y2. The Y receive linesare configured so that the left-most side of the touchscreen display hasa greater proportion of Y0 lines capacitively coupling with the X0 andX1 drive lines, while the center has a greater proportion of Y1 linesand the right side has a greater proportion of Y2 lines capacitivelycoupling with the X drive lines. Touchscreen circuitry can thereforedetermine whether a reduction in capacitive coupling is observed in theY0, Y1, or Y2 lines, or some proportional combination thereof, todetermine the horizontal finger position on the touchscreen display.

For example, if a finger is on the left-most side of the touchscreendisplay, it will touch regions of the X0 and X1 drive lines that aremost closely capacitively coupled to the Y0 receive lines. As the fingermoves to the right, it begins to come in contact with the region of theX1 line at 402 that is more closely capacitively coupled to the Y1receive line, eventually reaching the region of the X0 drive line at 401that is most closely capacitively coupled to the Y1 receive line.

This staggered transition from Y0 to Y1 electrodes as the finger movesfrom left to right provides a degree of interpolation between the Y0 andY1 regions also, because the Y lines in parallel with X1 transition fromY0 to Y1 before the Y lines in parallel with X0 transition from Y0 toY1. As the finger continues to move further right, it reaches regions inwhich the X drive lines alternately become more closely coupled to theY2 receive lines, such that the observed reduction in capacitancebetween the X drive lines and Y0, Y1, and Y2 receive lines can be usedto further determine the horizontal position of the finger on thetouchscreen display.

The touchscreens of FIGS. 2-4 have several advantages relative to thatof FIG. 1, including the lack of a resistive material coupling the Xdrive lines to interpolate X drive signals between the X drive lines.Fewer different materials and process steps arc therefore needed to formthe touchscreen display of FIGS. 2-4, and a reduced connection countsimplifies connection to external drive and control circuitry.

Because the X drive and Y receive lines in the examples such as FIG. 4do not overlap in the active area of the touchscreen, the entire activedisplay region of a two-dimensional touchscreen can be formed using asingle step, such as a single fine line metal deposition step, resultingin a relatively efficient and inexpensive production process. Further,as lines do not cross in the active area of the touchscreen, there areno regions of the touchscreen display that are more opaque than others,as there are no “stacked” or overlapping lines.

Although the snaking illustrated here comprises a regular series ofright angle turns, any variation in line direction or path from astraight line is considered snaking for purposes of the examplespresented here, including wavy lines, zig-zag lines, randomized lines,or any other such deviation from a straight line path. The degree ofsnaking varies between lines in the embodiments shown here, and cansimilarly be determined in a number of ways in various embodiments, suchas by determining the line length contained by a certain arearepresenting a finger touch, centered over the mean line path.

FIG. 5 illustrates a variety of alternate electrode pair snakingpatterns, as may be used in various touchscreen embodiments. At 501, azig-zag pair of drive and receive electrodes is formed, and at 502 awavy pair of electrodes is shown. Although the electrode pairs shown at501 and 502 snake by altering the route of a pair of continuous lineshaving no breaks for forks, 503 illustrates a snaking pattern in whichthe path of a pair of substantially parallel electrodes have snakingfeatures configured to increase the electrode line density in a givenarea by use of snaking features that fork off the main electrodes.

These examples of FIGS. 2-5 illustrate a variety of configurations inwhich the path an electrode pair takes across a touchscreen can bevaried or snaked to enable proportional position sensing by detectingthe relative change in capacitance in different drive and receiveelectrode pairs. This principle of mutual capacitance sensing can beobserved using a simple drive/receive electrode configuration asillustrated in FIG. 6. Here, a drive electrode 601 and a receiveelectrode 602 are coupled to a dielectric front panel 603, such as mayoverlay a typical touchscreen display assembly. The drive electrode 601is coupled to drive circuitry 604 that provides a series of drive pulses605 to the drive electrode, and the receive electrode 602 is coupled toreceive circuitry 606.

When the burst of pulses is provided to the drive electrode 601, thedrive electrode's proximity to receive electrode 602 causes capacitivecoupling between the two electrodes, and receive circuitry 606 canmeasure a charge between the drive and receive electrodes. When a fingeris present in the vicinity of the drive and receive electrodes, thefinger interferes with the capacitive coupling between the drive andreceive electrodes, causing the charge measured in receive circuitry 506to be reduced relative to the measured capacitance when a finger is notpresent.

Because the change in capacitance between the electrodes varies relativeto the proximity of the finger to the electrodes, touch can be detectedwhen a change in capacitance exceeds a certain threshold. Where morethan one pair of touchscreen electrodes such as those of FIG. 6 arepresent, touch can be distinguished by determining where the greatestchange in capacitance is observed, such as where a touch might otherwiseeffect multiple electrode pairs. In continuous region touchscreens suchas that of FIG. 4, the change in observed capacitance between variousdrive and receive electrodes varies proportionately between differentdrive and receive electrode pairs depending on the location of thefinger, as described in greater detail above.

A touchscreen display panel such as that of FIG. 4 can be used tooverlay a display, such as a liquid crystal display or OLED display, asshown in FIG. 7. Here, a display assembly 701 is viewed from the edge,with the visible image side facing up. A touchscreen 702 is formed onthe viewing surface of the display, and includes touchscreen electrodesand a cover to protect the various conductive components of thetouchscreen. In a more detailed example, the touchscreen 702 comprises adielectric protective layer covering a series of fine line metal wires,so that the fine wires only micrometers wide and thick are not damagedby physical contact.

Touchscreen displays such as that of FIG. 7 are often used in a varietyof applications, from automatic teller machines (ATM machines), homeappliances, personal digital assistants and cell phones, and other suchdevices. One such example cellular telephone and PDA device isillustrated in FIG. 8. Here, the cellular telephone device 801 includesa touchscreen display 802 comprising a significant portion of thelargest surface of the device. The large size of the touchscreen 802enables the touchscreen to present a wide variety of images that canserve along with touchscreen capability to provide input to the device,including a keyboard, a numeric keypad, program or application icons,and various other interfaces as desired.

The user may interact with the device by touching with a single finger,such as to select a program for execution or to type a letter on akeyboard displayed on the touchscreen display assembly 802, or may usemultiple touches such as to zoom in or zoom out when viewing a documentor image. In other devices, such as home appliances, the display doesnot change or changes only slightly during device operation, and mayrecognize only single touches at a time.

Although the example touchscreen display of FIG. 4 is configured as arectangular grid, other configurations are possible and are within thescope of the invention, such as a touchwheel, a linear slider, buttonswith reconfigurable displays, and other such configurations. Varying theproportionate density of snaked electrode pairs across the touchscreencan be adapted to any such shape, enabling detection of the region oftouch on the touchscreen.

Many materials and configurations will be suitable for formingtouchscreens such as those described herein, including fine line metalas in the examples above, as well as metal wire, conductive polymers,Indium tin oxide, and other materials in some embodiments. In sometouchscreens, it is desirable that the conductive material be eithertransparent, such as Indium tin oxide or transparent conductive polymer,or be so small as to not significantly interfere with visibility of thedisplay, such as with fine line metal.

Fine line metal wires in a more detailed example comprise wires that areapproximately 10 micrometers or less in width, or another similarsuitable size such as between 3-7 micrometers in width. The very smallline width enables placement of many lines per millimeter in someembodiments, as the total line density can in various embodiments covera fraction of a percent to 10% of the total screen area withoutsignificantly impacting the visibility of an image through thetouchscreen.

Although the snaking element touchscreen examples given here generallyrely on mutual capacitance to operate, other embodiments will use othertechnologies, including other capacitance measures such asself-capacitance of snaked lines, resistance, or other such sensetechnologies.

These example touchscreen assemblies illustrate how a touchscreen can beformed using snaking drive and receive lines that vary in line densityby snaking to various degrees. In some examples, the electrodes do notoverlap in the active area or field of the touchscreen, eliminating theextra materials, expense, and production steps needed to formresistively-coupled element touchscreens such as that of FIG. 1.

Configurations such as the example of FIG. 4 provide an efficient systemfor generating an accurate reading of a finger's location on evenrelatively complex two-dimensional touchscreens. These benefits simplifyoperation of the touchscreen panel, as fewer connections and lessfiltering and other data processing are needed to ensure reliabletouchscreen operation. This in turn leads to lower power consumption inan electronic device incorporating such a touchscreen display assembly,improving power efficiency, increasing battery life, and reducingresource use such as memory and processor consumption.

1. An assembly, comprising: an array of first electrode pairsdistributed across an active area of the touchscreen, the firstelectrode pairs decreasing in degree of snaking from electrode pair toelectrode pair in a first direction across the touchscreen; and an arrayof second electrode pairs distributed across an active area of thetouchscreen, the second electrode pairs increasing in degree of snakingfrom electrode pair to electrode pair in the first direction across thetouchscreen; wherein a position of a touch on the touchscreen can bedetermined in the first direction by the proportion of first and secondelectrode pair density in the area of the touch.
 2. The assembly ofclaim 1, wherein at least one electrode pair of the first and secondelectrode pairs comprises substantially parallel adjacent drive andreceive electrodes.
 3. The assembly of claim 1, wherein the number offirst and second electrode pairs are evenly distributed along the firstdirection.
 4. The assembly of claim 1, further comprising an extendedportion of the touchscreen extending the touchscreen in the firstdirection, and an array of third electrode pairs distributed across theextended portion of an active area of the touchscreen such that thethird electrode pairs increase in degree of snaking from electrode pairto electrode pair in the first direction across the extended portion ofthe touchscreen, and wherein the second electrode pairs are distributedacross the extended portion of the touchscreen such that the secondelectrode pairs decrease in degree of snaking from electrode pair toelectrode pair in the first direction across the extended portion of thetouchscreen.
 5. The assembly of claim 1, wherein at least one electrodeof the first and second electrode pairs comprises a fine line metalelectrode having a line width of 10 micrometers or less.
 6. The assemblyof claim 1, wherein the first and second electrode pairs arenonintersecting in the active area of the touchscreen.
 7. The assemblyof claim 1, wherein the electrodes of at least one of the electrodepairs interact via mutual capacitance to form a mutual capacitancetouchscreen.
 8. The assembly of claim 1, wherein at least one of thefirst and second electrode pairs comprises an array of receive elementsadjacent to and in parallel with a drive line electrode; such that thedensity of first receive elements adjacent to and in parallel with thedrive line electrode increases in a second direction not parallel thefirst direction; and the density of second receive elements adjacent toand in parallel with the drive line electrode decreases in the seconddirection.
 9. A method, comprising: providing a first drive signal to anarray of first drive electrodes distributed across an active area of atouchscreen, the first drive electrodes increasing in degree of snakingfrom electrode to electrode in a first direction across the touchscreen;providing a second drive signal to an array of second drive electrodesdistributed across an active area of the touchscreen, the second driveelectrodes decreasing in degree of snaking from electrode to electrodein the first direction across the touchscreen; and determining aposition of a touch on the touchscreen in the first direction bymeasuring the proportion of first and second drive electrode density inthe area of the touch.
 10. The method of claim 9, wherein the firstdrive electrodes are directly coupled to one another and to a firstexternal electrical connection and the second drive electrodes aredirectly coupled to one another and to a second external electricalconnection, and the number of first and second drive electrodes areevenly distributed across the touchscreen in the first direction. 11.The method of claim 9, further comprising an array of first receiveelectrodes adjacent to and in parallel with at least a portion at leastone of the first and second drive electrodes such that the drive andreceive electrodes are capacitively coupled, wherein measuring theproportion of first and second drive electrode density in the area ofthe touch comprises receiving a capacitively coupled drive electrodesignal from the array of first receive electrodes.
 12. The method ofclaim 11, wherein at least one of the first drive electrodes, seconddrive electrodes, and first receive electrodes comprise fine line metalelements having a line width of 10 micrometers or less.
 13. The methodof claim 11, further comprising: receiving a capacitively coupled driveline electrode signal from an array of second receive electrode adjacentto and in parallel with at least a portion of one of the first andsecond drive line electrode; wherein the density of first receiveelectrodes adjacent to and in parallel with at least a portion of one ofthe first and second drive line electrode increases in a seconddirection not parallel the first direction; and wherein the density ofsecond receive electrodes adjacent to and in parallel with at least aportion of one of the first and second drive line electrode decreases inthe second direction; and determining a position of a touch in thesecond dimension by evaluating the proportion of drive line signalcapacitively coupled to the first and second receive electrodes.
 14. Amethod, comprising: forming an array of first electrode pairsdistributed across an active area of a touchscreen, the first electrodepairs decreasing in degree of snaking from electrode to electrode in afirst direction across the touchscreen; and forming an array of secondelectrode pairs distributed across an active area of the touchscreen,the second electrode pairs increasing in degree of snaking fromelectrode to electrode in the first direction across the touchscreen;wherein a position in the first direction of a touch on the touchscreencan be determined by the proportion of first and second electrode pairdensity in the area of the touch.
 15. The method of claim 14, whereineach electrode pair of the first array of electrode pairs and secondarray of electrode pairs comprises at least one drive electrode and atleast one receive electrode.
 16. The method of claim 15, furthercomprising directly coupling drive electrodes in the array of firstelectrode pairs to one another and to a first external electricalconnection and directly coupling drive electrodes in the array of secondelectrode pairs to one another and to a second external electricalconnection, and wherein the number of first and second drive electrodesare evenly distributed across the touchscreen in the first direction.17. The method of claim 16, wherein at least one of the first driveelectrodes, second drive electrodes, and first receive electrodescomprise fine line metal elements having a line width of 10 micrometersor less, and wherein the first drive electrodes, second driveelectrodes, and first receive electrodes are nonintersecting in theactive area of the touchscreen.
 18. The method of claim 16, furthercomprising forming an array of second receive electrodes adjacent to andin parallel with at least a portion of one of the first and second driveline electrodes; such that the density of first receive electrodesadjacent to and in parallel with at least a portion of one of the firstand second drive electrodes increases in a second direction not parallelthe first direction; and the density of second receive electrodesadjacent to and in parallel with at least a portion of one of the firstand second drive electrodes decreases in the second direction.
 19. Anelectronic device, comprising: a display; a touchscreen assemblyoverlaying the display, the touchscreen assembly comprising: an array offirst electrode pairs distributed across an active area of thetouchscreen, the first electrode pairs decreasing in degree of snakingfrom electrode pair to electrode pair in a first direction across thetouchscreen; and an array of second electrode pairs distributed acrossan active area of the touchscreen, the second electrode pairs increasingin degree of snaking from electrode pair to electrode pair in the firstdirection across the touchscreen; wherein a position of a touch on thetouchscreen can he determined in the first direction by the proportionof first and second electrode pair density in the area of the touch. 20.The electronic device of claim 19, wherein the device comprises at leastone of a cellular telephone, a personal digital assistant, an appliance,a computer, an automatic teller machine, and a kiosk.